Method of blending materials in the making of briquets



Patented 2a, 1932 r for fuel, an

UNITED STATES paras-rename CLAYTON I. WOLI', OI IILBOSE HIGHLANDS. IABSACHUIITTS, AS31810] TO mama! BBIOUE'I 001mm, A CORPORATION OI DILAWABI mnon OI WING THRILL! DI THE m6 OI BBIQUI'I'I Io Drawing.

and mixed and said distribution and mixing I is made stable.

While the method is applicable to various materials in the production of briquets, it is especially a plicable to briquets produced which are formed of different kinds of coal, and a suitable binder.

As a specific example of my invention I will describe my method of mixing or-blending a small percent of coking coal with nonbindenwhich alsoresults in certain improve-. ment in the binder as well.

I have found that, if finely pulverized coking soft coal, no particles of which exceed sixty mesh in size, is added to the binder,

which contains a hydro-carbon, and the whole agitated for about one minute or even less, the finely pulverized coal particles will afiiliate themselves with the hydro-carbon particles approximately in proportion to the size of the hydro-carbon particles. This results in a very even distribution of the soft coal particles throughout the batch of binder which consists of afiliated soft coking coal particles and hydro-carbon articles uniformly mixed or dispersed in t e binder constituents.

Furthermore it has been found that such coking soft or bituminous coal can be added in such quantities to the binder that addition of 10 to 14% of such binder to the noncoking fuel will result in a ratio of 7 parts coking coal to 93 parts non-coking fuel. Such a binder will also have a low enough viscosity to permit its being pumped through a conventional type of binder pump.

By virtue of the fact that the art of mixing or fluxing of a binder. with a. fine fuel has been developed to a high degree of perfection, resulting in a very uniform distribution of such a binder throughout the fine fuel particles, and by virtue of the fact that the mixing of (60 mesh or finer) bituminous coking coal results in a very uniform distribution of the bituminous coal throughout the els through the medium of the Application fled August 81, 1929; Serial Io. 887,565.

binder, it is apparent that introduction. of a coking bituminous coal into non-co fine fuel through the medium of the binder as described, will result in a thorough and intimate mixture or distribution of said bituminous coal throughout the non-coking fine coal or fuel.

Briquets prepared in this manner, resulting 1n a final ratio of 7 parts coking coal to 93 parts non-coking anthracite culm,when compared with briquets made in the conventional way by dry mixing of coln'ng coal and non-coking anthracite culm,when rtly consumed in the fire, have been foun to be harder, due to the fact that the dispersion or distribution of the coking coal thro hout the non-coking anthracite was more uni orm, resulting in a more uniform and coherent coke matrix throughout the partially con sumed briquet;

A refinement on the above-mentioned method: I

When an emulsion binder is used, containing a hydro-carbon such as petroleum asphalt or coa tar, pitch, and any suitable carbohydrate paste such as corn starch, tapioca or rice, the viscosity of the hot starch paste is at proximately that of the as haltum, and addition of a coking soft coa as just described obviously increases the viscosity of the binder uite materially. It is apparent therefore t at if prior to introduction or during introduction of the coking coal. or subsequently, the viscosity of the starch paste, organic a hesive or dispersing medium could be lowered without impairing the adhesive properties of the same, and without effecting the stability of the dispersion of the afiiliated coal and hydro-carbon particles, that the viscosity of the binder would be lowered accordingly,

It is well known that if a starch aste such as corn, tapioca, rice, etc. is su jected to 500 F. for one hour at atmos herie pressure, the starch will be completely extrinized. It

has been found that the viscosity of the resultant dextrin solution is considerably lower than the viscosity of the original starch aste.

I have found that if the emulsifier. e so designed that all openings from the same to the atmosphere can be quickly closed by means of suitable gate valves of conventional design, and the steam jacket of the emulsifier designed to carry steam at a superheat of approximately 530 F. (which is a normal and not difiicult superheated steam pract1ce) that if, immediately after introduction of the coking bituminous coal to the binder the said valves are closed, the temperature oi the emulsion in the emulsifier will quickly rise to approximately 300 F., developing a pressure Within the same of approximately 3 atmospheres or approximately 45 lbs. gauge pressure. This is what, in industrial practice, is commonly called autoclaving. The additional time required to accomplish the proper amount of autoclaving depends upon the nature of the emulsion which it is desired to obtain. Autoclaving for a period of about 4 minutes, which produced a pressure of about two atmospheres, produces a binder which gives very satisfactory results.

The resultant binder from such procedure has these distinctive characteristics.

1. Its viscosity is considerably lower than when prepared without the autoclaving or pressure cooking. The reaction herein involved is not fully understood but it is believed that the rise in temperature, combined with the increase in pressure, combined with the continuous agitation, dextrinizes orotherwise affects part of the starch or other organic adhesive medium, and thereby lowers the viscosity of the solution.

2. The coal particles appear to take on a closer afiiliation with the hydrocarbon particles, which may be due to partial solution of some of the soluble volatile matter of the coal into the oil constituents of the hydrocarbon or asphaltum. 3. The aifiliated coal and hydrocarbon particles appear under the microscope and even to the naked eye to be of remarkably uniform sizes or diameters and to be very uniformly dispersed throughout the starch paste or organic adhesive medium.

4. Such a binder if allowed to cool will, as is normal, result in a setting up or jelling of the paste, but is exceptional in that it will preserve the uniformity of the dispersion or emulsion for a matter of three or four days.

What I claim is 1. The method of blending materials in the making of briquets which consists in intimately mixing with an emulsion binder, which is an emulsion of any suitable hydrocarbon such as pertoleum asphalt or coal tar pitch, in any suitable carbohydrate paste such as cornstarch, tapioca or rice, a small per cent of pulverized coking coal and then coal parmixing said binder and the coking arger per ticles suspended therein, with a cent of pulverized non-coking coal.

2. The method of blending materials in the making of briquets which consists in mixing with an emulsion binder, which is an emulsion of any suitable h dro-carbon such as petroleum asphalt or coa tar pitch, in any suitable carbohydrate paste such as cornstarch, tapioca or rice, a small per cent of pulverized coking coal and agitating the same while subjected to a temperature not less than 200 F. and pressure not less than one pound gage above atmosphere, and then mixing said binder and the coking coal particles suspended therein, with a larger per cent of pulverized non-coking coal.

3. The method of blending materials in the making of briquets which consists in mixing with an emulsion binder, which is an emulsion of any suitable hydro-carbon such as petroleum asphalt or coal tar pitch, in any suitable carbohydrate paste such as cornstarch, tapioca or rice, a small per cent of pulverized coking coal and agitating the same While subjected to a temperature of approximately 300 F. and a pressure of approximately three atmospheres, and then mixing said binder and the coking coal particles suspended therein, with a larger per cent of pulverized non-coking coal.

4. The method of blending materials in the ratio approximately of seven parts to ninety-three parts in the making of briquets which consists in mixing with an emulsion binder, which is an emulsion of any suitable hydro-carbon such as petroleum asphalt or coal tar pitch, in any suitable carbohydrate paste such as cornstarch, tapioca or rice, approximately seven parts of pulverized coking coal and then mixing said binder and the coking coal particles suspended therein, with approximately ninety-three parts of pulverized non-coking coal.

CLAYTON S. WOLF. 

